Fahrenheit (°F) - Unit Information & Conversion

Definition

Degree Fahrenheit (°F) is a unit of temperature on the Fahrenheit scale, a temperature scale developed by Daniel Gabriel Fahrenheit. On this scale, the freezing point of water is defined as 32°F and the boiling point as 212°F, placing the two points 180 degrees apart. It is primarily used in the United States and a few other countries for everyday temperature measurements.

History

The Fahrenheit scale was proposed in 1724 by the physicist Daniel Gabriel Fahrenheit. He initially defined 0°F based on the temperature of a brine solution (ice, water, and ammonium chloride) and set human body temperature at 96°F. Later refinements adjusted the scale so that water's freezing point was exactly 32°F and boiling point exactly 212°F.

Common Uses

• US Weather: Everyday weather reporting and forecasting in the United States and its territories.
• US Domestic: Domestic temperature settings (thermostats, ovens) in the US.
• US Medical: Medical temperature measurements in the US.
• US Culinary: Some cooking applications, particularly in recipes originating from the US.

Unit FAQs

Why is the freezing point of water 32°F?

Fahrenheit's initial scale used different reference points. When the scale was later standardized using water, the freezing point landed at 32°F based on the original scale's divisions.

How does Fahrenheit relate to Celsius?

The relationship is linear but involves an offset. To convert Fahrenheit to Celsius, use the formula: °C = (°F - 32) * 5/9. To convert Celsius to Fahrenheit: °F = (°C * 9/5) + 32.

Where is Fahrenheit still commonly used?

The United States is the primary country that uses Fahrenheit for everyday temperature measurements. It's also used in some Caribbean countries and US territories like Puerto Rico, Guam, and the U.S. Virgin Islands. Most other countries use Celsius.